Lemon Zucchini Coffee Cake

Preheat oven to 350ºF. Grease the sides and bottom of an 8- to 9-inch springform pan.

For the topping, stir flour, sugar, zest, and salt. Add butter, pressing into the dry ingredients with your fingertips until butter pieces are small and distributed throughout. Set aside.

For the cake, whisk flour, zest, baking powder, baking soda, and salt. In another bowl, whisk melted butter, oil, sugar, sour cream, lemon juice, and vanilla until smooth. Whisk in eggs. Add flour mixture to wet ingredients, stirring just until combined. Fold in zucchini.

Pour batter into the prepared pan, smoothing evenly. Sprinkle crumb topping over the top.

Bake for 45–55 minutes until set in the center. Let cool in the pan for 10 minutes. Run a thin knife along the edge of the pan, then remove the springform side.

For the glaze, whisk powdered sugar with lemon juice and milk. Adjust consistency with more sugar or milk/juice as needed. Spoon over the warm cake.

Once completely cooled, wrap tightly in foil and let rest at room temperature overnight.